As is well known, a thin film transistor-liquid crystal display (TFT-LCD) is one of the current main flat panel display products, and has become an important display platform in modern information technology and video products. As a liquid crystal itself does not emit light, a backlight module is required to realize the display function of the liquid crystal.
At present, the relatively mainstream backlight module adopts a side type backlight. In this type of backlight, light bars (LB) consisting of light-emitting diodes (LEDs) and an aluminium extruded section are arranged on the lateral surfaces of a backlight frame. Then, light is transmitted to a display area through a light guide plate (LGP) mounted on the backlight frame. Afterwards, the light passes through an optical diaphragm, such as a prism or a diffuser, and finally forms a uniform light source.
As shown in FIG. 1, a commonly-used light guide plate at present is mounted on the backlight frame in such a manner that when the light guide plate 13 is cut, protrusions 14 or grooves (only protrusions 14 shown in the figure) are formed on the top and bottom sides (namely two sides along the transverse direction indicated by the direction T in FIG. 2) of the light guide plate 13 respectively. Then, corresponding grooves 15 or corresponding protrusions (only grooves 15 shown in the figure) are formed on two sides of the backlight frame 11 along the transverse direction respectively, and form a shape-complementary fit with the protrusions 14 or grooves on the light guide plate 13 respectively. Therefore, the light guide plate 13 can be secured in the backlight frame 11. Meanwhile, light bars 12 are arranged on two sides of the backlight frame 11 along the longitudinal direction (i.e., the direction L shown in FIG. 2), respectively.
However, with such a mounting manner, the protrusions or the grooves need to be directly formed when the light guide plate is cut, so that the light guide plate has to be cut in an irregular way. Therefore, the utilization of raw material for the light guide plate to be cut will be reduced, and the production cost will be raised at last.